Final reg-alloc across chapters cleanup

4 files changed, 32 insertions, 2 deletions

diff --git a/chapter20/src/main/java/com/seaofnodes/simple/codegen/IFG.java b/chapter20/src/main/java/com/seaofnodes/simple/codegen/IFG.java
index acfec53f..71a96d94 100644
--- a/chapter20/src/main/java/com/seaofnodes/simple/codegen/IFG.java
+++ b/chapter20/src/main/java/com/seaofnodes/simple/codegen/IFG.java
@@ -494,7 +494,7 @@ abstract public class IFG {
             if( reg == -1 && alrg._mask.size1() )
                 reg = alrg._mask.firstReg();
             if( reg != -1 ) {
-                mask.clr(alrg._reg);
+                mask.clr(reg);
                 if( mask.size1() )
                     return mask.firstReg();
             }
diff --git a/chapter20/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemOpX86.java b/chapter20/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemOpX86.java
index dee4afd4..f65fe054 100644
--- a/chapter20/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemOpX86.java
+++ b/chapter20/src/main/java/com/seaofnodes/simple/node/cpus/x86_64_v2/MemOpX86.java
@@ -66,7 +66,7 @@ public abstract class MemOpX86 extends MemOpNode implements MachNode {
         if( i==1 ) return null;               // Memory
         if( i==2 ) return x86_64_v2.RMASK;    // base  in GPR
         if( i==3 ) return x86_64_v2.RMASK;    // index in GPR
-        if( i==4 ) return x86_64_v2.MEM_MASK; // value in GPR or XMM
+        if( i==4 ) return _sz >= '4' ? x86_64_v2.MEM_MASK : x86_64_v2.RMASK; // Narrow stores need GPRs
         throw Utils.TODO();
     }
 
diff --git a/chapter20/src/test/java/com/seaofnodes/simple/Chapter20Test.java b/chapter20/src/test/java/com/seaofnodes/simple/Chapter20Test.java
index 00a8407f..71a4bc36 100644
--- a/chapter20/src/test/java/com/seaofnodes/simple/Chapter20Test.java
+++ b/chapter20/src/test/java/com/seaofnodes/simple/Chapter20Test.java
@@ -10,6 +10,23 @@ import static com.seaofnodes.simple.Main.PORTS;
 import static org.junit.Assert.*;
 
 public class Chapter20Test {
+    @Test public void testAllocatorFixedNeighbor() throws Exception { com.seaofnodes.simple.codegen.RegAllocTestSupport.uncoloredFixedNeighbor(); }
+
+    @Test public void testNarrowStoreMasks() {
+        for( String type : new String[]{"i8","u8","i16","u16"} ) {
+            CodeGen code = new CodeGen("struct S { "+type+" x; }; S !s=new S; s.x=arg; return 0;")
+                .parse().opto().typeCheck().instSelect(PORTS,"x86_64_v2","SystemV").GCM().localSched().regAlloc();
+            int stores=0;
+            for( var bb : code._cfg )
+                for( var node : bb.outs() )
+                    if( node instanceof com.seaofnodes.simple.node.cpus.x86_64_v2.StoreX86 st ) {
+                        stores++;
+                        assertEquals(-1,st.regmap(4).nextReg((short)15));
+                    }
+            assertEquals(1,stores);
+        }
+    }
+
     @Test public void testInlinedReturnValue() {
         String src = """
 struct S { int x; };
diff --git a/chapter20/src/test/java/com/seaofnodes/simple/codegen/RegAllocTestSupport.java b/chapter20/src/test/java/com/seaofnodes/simple/codegen/RegAllocTestSupport.java
index bb1d49bf..1b3963c5 100644
--- a/chapter20/src/test/java/com/seaofnodes/simple/codegen/RegAllocTestSupport.java
+++ b/chapter20/src/test/java/com/seaofnodes/simple/codegen/RegAllocTestSupport.java
@@ -30,6 +30,19 @@ public class RegAllocTestSupport {
         return code;
     }
 
+    public static void uncoloredFixedNeighbor() throws Exception {
+        CodeGen code = graph();
+        RegAlloc alloc = new RegAlloc(code);
+        Op def = new Op(new RegMask(3L),null,null,false,code._start);
+        LRG lrg = alloc.newLRG(def);
+        LRG neighbor = new LRG((short)99);
+        neighbor._mask = A;
+        lrg.addNeighbor(neighbor); // Uncolored, but its only possible color is A.
+        var bias = IFG.class.getDeclaredMethod("biasColorNeighbors",RegAlloc.class,Node.class,RegMask.class);
+        bias.setAccessible(true);
+        assertEquals((short)1,bias.invoke(null,alloc,def,new RegMaskRW(3L,0L)));
+    }
+
     public static void masks() {
         for( int reg : new int[]{0,63,64,65,127} ) {
             RegMask mask = new RegMask(reg);